Asthma sufferers number approximately 200 million worldwide, with 15-20 million of those in the United States. Multiple comorbid conditions occur with asthma, including rhinitis, rhinosinusitis, gastroesophageal reflux disease, sleep apnea, vocal cord dysfunction syndrome, obesity, and chronic obstructive pulmonary disease (COPD). Without identifying and caring for comorbid conditions, asthma cannot be treated appropriately. Comorbidity of allergic diseases emphasizes that we must understand more about why different organs in individuals express allergy and others do not. The increase in multiple allergies occurring in a single patient makes the global burden even more complex, and an integrated approach to diagnosis and new treatment strategies and preventative approaches are required. Asthma: Comorbidities, Coexisting Conditions, and Differential Diagnosis is the first volume to provide a centralized, a comprehensive clinical reference on the diagnosis and management of the comorbid conditions that affect asthma. Because comorbid conditions of asthma have not yet been included in international and national management guidelines, this volume will help fill a gap in current clinical knowledge, aiding physicians in delivering optimal patient care.